LibEspresso: be more robust to context enter/leave/close errors

Author: gilles-duboscq

espresso/src/com.oracle.truffle.espresso.libjavavm/src/com/oracle/truffle/espresso/libjavavm/LibEspresso.java

@@ -111,6 +111,11 @@ static int createJavaVM(@SuppressWarnings("unused") IsolateThread thread, JNIJav
                 context.close(true);
             }
             return JNIErrors.JNI_ERR();
+        } catch (IllegalArgumentException e) {
+            // This can happen during option processing (build call above)
+            // OptionType converters can throw IllegalArgumentException
+            STDERR.println(e.getMessage());
+            return JNIErrors.JNI_ERR();
         }
         Value java = bindings.getMember("<JavaVM>");
         if (!java.isNativePointer()) {
@@ -161,7 +166,12 @@ static int enterContext(@SuppressWarnings("unused") IsolateThread thread, JNIJav
             STDERR.println("Cannot enter context: no context found");
             return JNIErrors.JNI_ERR();
         }
-        context.enter();
+        try {
+            context.enter();
+        } catch (PolyglotException | IllegalStateException e) {
+            STDERR.println("Cannot enter context: " + e.getMessage());
+            return JNIErrors.JNI_ERR();
+        }
         return JNIErrors.JNI_OK();
     }
 
@@ -173,7 +183,12 @@ static int leaveContext(@SuppressWarnings("unused") IsolateThread thread, JNIJav
             STDERR.println("Cannot leave context: no context found");
             return JNIErrors.JNI_ERR();
         }
-        context.leave();
+        try {
+            context.leave();
+        } catch (IllegalStateException e) {
+            STDERR.println("Cannot leave context: " + e.getMessage());
+            return JNIErrors.JNI_ERR();
+        }
         return JNIErrors.JNI_OK();
     }
 
@@ -189,8 +204,13 @@ static int closeContext(@SuppressWarnings("unused") IsolateThread thread, JNIJav
         ObjectHandle contextHandle = javaVM.getFunctions().getContext();
         Context context = ObjectHandles.getGlobal().get(contextHandle);
         ObjectHandles.getGlobal().destroy(contextHandle);
-        context.leave();
-        context.close();
+        try {
+            context.leave();
+            context.close();
+        } catch (PolyglotException | IllegalStateException e) {
+            STDERR.println("Cannot close context: " + e.getMessage());
+            return JNIErrors.JNI_ERR();
+        }
         return JNIErrors.JNI_OK();
     }